And why do they do it? What are they trying to achieve?
I'd guess that they most likely want multiple people to be able to access a single account. Passwords are forced to be shared because a password is typically implemented as a single credential - there's one valid password for that account.
This is .... not true for passkeys. If you want two people to access the same account, they both add passkeys to that account.
Sharing passwords happen because of a property of passwords. It's not some fundamental requirement that people have. What people want is shared access.
How do you bootstrap the system? Presumably your spouse/partner/friend and you use different computers? With 1password I can just share passkeys in the UI.
I'd guess that they most likely want multiple people to be able to access a single account. Passwords are forced to be shared because a password is typically implemented as a single credential - there's one valid password for that account.
This is .... not true for passkeys. If you want two people to access the same account, they both add passkeys to that account.
Sharing passwords happen because of a property of passwords. It's not some fundamental requirement that people have. What people want is shared access.